If field includes a comma or a new line, the whole field must be surrounded with double quotes. When the field is in quotes, any quote literals must be escaped by \" Backslash literals must be escaped by \\. Otherwise a backslash an the character following it will be treated as the following character, ie."\n" is equivelent to "n". Other escape sequences may be set using the setEscapes() method. Text that comes after quotes that have been closed but come before the next comma will be ignored.
Empty fields are returned as as String of length zero: "". The following line has three empty fields and three non-empty fields in it. There is an empty field on each end, and one in the middle. One token is returned as a space.
,second,, ,fifth,
Blank lines are always ignored. Other lines will be ignored if they start with a comment character as set by the setCommentStart() method.
An example of how CVSLexer might be used:
CSVParser shredder = new CSVParser(System.in); shredder.setCommentStart("#;!"); shredder.setEscapes("nrtf", "\n\r\t\f"); String t; while ((t = shredder.nextValue()) != null) { System.out.println("" + shredder.lastLineNumber() + " " + t); } Some applications do not output CSV according to the generally accepted standards and this parse may not be able to handle it. One such application is the Microsoft Excel spreadsheet. A separate class must be use to read Excel CSV. @see com.Ostermiller.util.ExcelCSVParser
Implementation is based on a state-machine that pulls information using {@link CsvReader}.
Delimited Text Parser
Parses a delimited text file into a memory array
@author Sergio Montoro Ten @version 6.0To parse CSV input in a format like Excel, you write:
CSVParser parser = CSVParser.parse(csvData, CSVFormat.EXCEL); for (CSVRecord csvRecord : parser) { ... } If the predefined formats don't match the format at hands, custom formats can be defined. More information about customising CSVFormats is available in {@link CSVFormat CSVFormat JavaDoc}.
If parsing record wise is not desired, the contents of the input can be read completely into memory.
Reader in = new StringReader("a;b\nc;d"); CSVParser parser = new CSVParser(in, CSVFormat.EXCEL); List<CSVRecord> list = parser.getRecords(); There are two constraints that have to be kept in mind:
Internal parser state is completely covered by the format and the reader-state.
@version $Id: CSVParser.java 1617069 2014-08-10 08:53:42Z britter $ @see package documentation for more detailsThis class parses comma-separated, optionally quoted data from a String and returns the parsed fields as an array of Strings.
The set of quote characters and the field delimiter character are configurable.
The class can optionally trim the fields with String.trim() before returning them.
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